This invention relates to roller conveyors used to provide rolling movement of cargo over the floor of a cargo deck, and in particular to modular roller trays and roller housings.
Roller or ball mats have been used on cargo deck floors in aircraft to provide rolling movement of cargo carrying units such as cargo containers or pallets from the aircraft doorway to the cargo unit's final loaded position. Prior roller mats include an extruded frame in which a plurality of rotatable roller elements are mounted. However, the roller elements and their mounting mechanisms often become damaged during use and fail to operate properly. Prior roller mats require substantial disassembly in order to repair or replace individual roller units which have failed.
U.S. Pat. No. 3,763,980 discloses an assembly set for erecting roller conveyors. Each assembly set is connected to an adjacent assembly set by connector members disposed in the side walls of the assembly sets. In this fashion, a ball mat is constructed by interlinking a series of assembly sets.
The present invention provides a modular roller mat having lower maintenance and lower manufacturing costs than former designs. The roller mat is comprised of a plurality of interconnected trays with each tray including a plurality of individual roller assembly units. The roller assembly units are interchangeable with one another and are easily removed and replaced in a tray. If a roller assembly unit fails it may be replaced by another unit with minimum downtime. Furthermore, the consistency between the modular roller assembly units offers cost advantages through economies of scale and a reduction of the inventory required to support an aircraft or other location where the roller mats are employed to transport cargo.